1. Field of the Invention
The present invention is directed toward carpet cushion underlay materials. In particular, the carpet underlay features a supportive multilayered pad or mat comprising a primary sheet of resilient viscoelastic polyurethane memory foam adhered to a non-woven carrier having a subjacent non-slip surface.
2. Description of the Prior Art
Carpet underlay materials have been extensively sold at retail venues and provide a degree of comfort and non-slip protection for area rugs that are situated upon hard flooring surfaces. It is not uncommon for such flooring to have generally smooth characteristics, which are typically fabricated from wood, stone, tile or vinyl laminates. To enhance the inherent luster of laminated floor coverings, consumers will apply polishing solutions that may cause the above noted surfaces to become very slippery. Emulsion polymers are the major component used to form the film in floor polish, along with polyethylene and/or polypropylene waxes, which are added to improve the wear resistance of these formulations. To facilitate the uniform coverage of floor polishes to the widest range of flooring substrates, manufacturers will commonly utilize fluorosurfactants, in combination with plasticizers like tributoxyethyl phosphate (TBEP), to essentially lower the surface tension of comparable suspensions. By lowering the surface tension, such formulations will evenly coat a broader array of substrates, but may materially cause decorative rugs to glide across polished flooring without the use of a non-slip pad or mat.
One type of nonslip rug underlay in the prior art consists of a knitted polyester scrim featuring a coating of thermally foamed polyvinyl chloride (PVC) resin. The knitted construction of the scrim provides an arrangement of woven yarns defining a pattern of apertures that correspond to a configuration of openings extending through the thickness of the cured PVC material. Alternatively, the PVC resin may be knife coated to either side of a knitted scrim devoid of openings, or to a non-woven fabric of bonded fibers, producing a continuous layer of supported foam. The PVC compound also includes a plasticizer that imparts a removable nonslip mechanical bond between the rug underlay and a subjacent surface. Although such underlay materials provide a degree of protective nonslip cushioning for area rugs, the formulation of the cured PVC compound may negatively react with plasticizer additives in floor polishes, or may adversely solvate with the lacquered finishes of hardwood flooring, causing inadvertent surface damage to occur.
Another type of non-slip rug underlay in the prior art is made up of a fibrous mat that is coated with a non-skid backing of natural rubbers or foam latex embossed with a geometric formation. For example, U.S. Pat. No. 6,200,662, issued on Mar. 13, 2001 to C. Mussallem, III, discloses a rug underlay comprising a synthetic fiber batting that is needle-punched to form a compressed mat structure. The composition does not include a scrim or stiffening lattice, and the upper layer of fibers are heat fused by a drum to provide a chevron design of alternating lands and grooves to grip the underside of an area rug. Similarly, U.S. Pat. No. 6,440,341, issued on Aug. 27, 2001 to the same inventor, discloses a rug underlay consisting of a man-made fiber batting that is needle-punched to form a condensed layer of unsupported material. The upper surface of the substrate is flame-treated to produce an arrangement of melted filaments having random extending projections of fiber that cling to the bottom of a throw rug. In each disclosure, a non-slip coating of rubber or a foamed elastomeric resin is disposed on the reverse side of the rug underlay material.
Yet another provision known in the prior art includes rug underlay materials that are composed of flexible open-cell polyurethane foams. Polyurethane foam is manufactured as the product of the reaction of two key raw materials, a polyol and a diisocyanate with water. In the production of rug or carpet underlay, a uniform layer of foam is produced through the slabstock method, wherein a mixture of polyol and diisocyanate is poured onto a moving conveyor where it reacts and expands to form a continuous slab of material. Alternatively, the rug underlay may be composed from recycled foam that is ground into small particle sizes and made into a flexible bonded polyurethane padding.
U.S. Pat. No. 5,721,035, issued on Feb. 24, 1998 to E. Dunn, discloses a carpet underlay cushion structure comprising a carrier layer of an open-cell polyurethane foam material that is uniformly impregnated with a carboxylated styrene-butadiene rubber (SBR) latex blend. A woven substrate is pressed and/or adhered onto the surface of the polymeric composition, which is subsequently dried and cured with the latex blend to produce a resilient open-cell structure. The woven substrate enhances the dimensional stability of the polyurethane foam layer so that it may be effectively used as a carpet underlay material.
U.S. Pat. No. 5,114,773, issued on May 19, 1992 to J. Bogdany, discloses an open-cell foam composite structure and method for making a carpet cushion underlay. The open-cell material includes a polyurethane foam carrier layer that is impregnated with a polymer-containing composition. As indicated in the specification of the patent, the composition may be formulated from polyvinyl chloride, polyvinyl acetate, polypropylene or vinyl acetate resins. The polymeric composition is applied by way of a reverse roll applicator which compresses the polyurethane carrier to saturate the foam material. The compressed composite foam structure is then released, and may be thermally cured to dry the imbued polymeric resin. To enhance the dimensional stability and mechanical properties of the carpet cushion structure, a woven scrim is laminated to the composition by adhesive or by the dried impregnant. U.S. Pat. No. 4,957,798, also issued to J. Bogdany on Sep. 18, 1990, is directed to a similar process and product wherein a non-carboxylated styrene-butadiene rubber (SBR) is suffused into the polyurethane foam carrier.
U.S. Pat. No. 4,816,494, issued on Mar. 28, 1989 to S. Watson, Jr. et al., discloses a flexible, densified polyurethane foam cushioning material. The homogeneous polymeric composition is produced through the partial curing of a polyol polyurethane foam-forming mixture under a compressive force to control and minimize the volume of the expanding formulation. The compressive force is subsequently removed to finalize the curing of the condensed cellular structure. The disclosure does not make a provision for the use of a scrim backing or other supplemental substrate layer to control the dimensional stability of the foam.
U.S. Patent Application Publication US 2011/0143083 Al by I. Scorgie, published on Jun. 16, 2011, exemplifies yet another embodiment within this field. The inventor discloses a cushioned, absorbent mat comprising a surface layer of woven microfiber textile containing a core layer of viscoelastic polyurethane foam. The microfiber material is woven from a plurality of absorptive woven polyester and nylon strands that impede the passage of moisture into the open cell structure of the polyurethane foam. As indicated in the specification, the permeable microfiber surface layer is intended to wick moisture away from the underlying polyurethane foam. A nonslip rubberized base material is secured to the second side of the cushioning layer, and configured to allow the mat to be securely positioned on a floor surface. The purpose of this mat is to be that of a standalone product capable of absorbing moisture and accelerating the drying process when exiting a shower or bath.
The systems, methods, and inventions described in the above-identified patent publications are found lacking in disclosing an improved multilayered carpet underlay, which comprises a resilient viscoelastic polyurethane foam that is laminated to a non-woven carrier having a subjacent non-slip surface.
Accordingly, it is a principal object of the present invention to provide a supportive underlay for area rugs and carpets having improved comfort and mechanical non-slip properties over needle-punched fibrous mats, or underlay materials that are primarily composed of open-cell polyurethane foams.
It is a further object of the invention to provide a supportive underlay for area rugs and carpets having a top layer of viscoelastic polyurethane memory foam that is either coated or compounded with an antioxidant, or other suitable stabilizer, to inhibit the discoloration of the polymeric foam.
It is yet another object of the invention to provide a supportive underlay for area rugs and carpets that uses a fibrous needle-punched carrier to reinforce the dimensional stability of the polyurethane foam layer.
It is an additional object of the invention to provide a supportive underlay for area rugs and carpets that incorporates a flexible adhesive layer to effectively bond the viscoelastic memory foam to the fibrous needle-punched carrier.
Finally, an object of the invention is to provide a supportive underlay for area rugs and carpets having a coating or an imprinted layer of a nonslip polymeric resin applied to the subjacent surface of the needle-punched carrier.